//package Filter;
//
//import javax.servlet.FilterChain;
//import javax.servlet.ServletException;
//import javax.servlet.ServletRequest;
//import javax.servlet.ServletResponse;
//import javax.servlet.annotation.WebFilter;
//import javax.servlet.http.HttpFilter;
//import javax.servlet.http.HttpServletRequest;
//import javax.servlet.http.HttpServletResponse;
//import java.io.IOException;
//
//
//@WebFilter("/login/dgut")
//public class TokenFilter extends  HttpFilter{
//    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException{
//
//        HttpServletRequest req = (HttpServletRequest) request;
//        HttpServletResponse resp = (HttpServletResponse) response;
//
//        String token = req.getParameter("token");
//        if(token == null) {
//            resp.sendRedirect("https://cas.dgut.edu.cn?appid=javaee&state=STATE");
//        }
//        else
//            chain.doFilter(req, resp);
//    }
//}